Am I right or what? You either gotta be extremely confident or extremely pretty to call yourself Pretty Boy. Which one is Mayweather, extremely pretty or extremely confident?

The only reason he got the name was because there is an infamous gangster named Pretty Boy Floyd. If Floyd's name had not been Floyd, he would not be called Pretty Boy, I bet a million dollars, his name would have been something like Elusive or something along those lines.

Pretty Boy Floyd
American gangster
byname of Charles Arthur Floyd

born Feb. 3, 1904, Bartow County, Ga., U.S.
died Oct. 22, 1934, near East Liverpool, Ohio

American gunman whose run-ins with police and violent bank robberies made newspaper headlines.

In 1911 Floyd moved with his family to Oklahoma, eventually settling in Akins. Originally a farmer, he was drawn into crime by the poverty of the Dust Bowl. After serving a term in prison (1925–29) for a payroll robbery, Floyd mixed with gangsters in Kansas City, Missouri, and adopted the machine gun as his professional trademark. He teamed up with others to rob banks in Ohio (where he was captured in 1930, but subsequently escaped), Michigan, and Kentucky. After nearly being apprehended by the police in 1931, Floyd returned to Oklahoma, where he was protected by the locals who called him “the Robin Hood of the Cookson Hills” for his destruction of mortgage papers during bank robberies. Floyd’s criminal activities continued, and in 1933 he was accused of participating in the Union Station massacre, in which three police officers, an FBI agent, and a prisoner were killed. Though Floyd denied involvement in the incident, authorities intensified efforts to capture him, and the following year he was gunned down by FBI agents who were pursuing him in an Ohio field. There has been some speculation that Floyd was initially just wounded, and it was only after refusing to answer questions that he was fatally shot by a federal agent.